This application is a Continuation-in-Part of copending U.S. Pat. application Ser. No. 232,661 filed Mar. 8, 1972.
This application relates generally to fluid dispensing systems and more particularly to a cartridge type control valve for use in the dispensing head for such systems having a substantial number of elements therein made of plastic material.
In U.S. Pat. No. 3,493,010 a review was made of prior art cartridge type control valves used in the dispensing head of fluid dispensing systems as shown in U.S. Pat. Nos. 1,793,292; 2,868,233; 3,089,510 and 3,003,519 and the problems concerning cost of the materials used in such prior art control valves and the problems of manufacture and assembly with such materials was fully set forth.
In U.S. Pat. No. 3,493,010 a control valve was disclosed having a multi-part fluid transfer assembly forming respectively the fluid transfer chamber and inlet duct, made of plastic, which coacted with an associated valve actuating means. This control valve was an assembled or built up arrangement. Accordingly, it required a sufficiently different mounting bore in the dispensing head to the extent that the control valve of U.S. Pat. No. 3,493,010 could not be easily mounted in the existing castings or forgings of dispensing heads adapted to receive the prior art type cartridge control valves nor could it be substituted as a replacement part for existing prior art cartridge type control valves when replacement due to defects or other causes was required.
The present invention relying on new methods of manufacture which are applicable to plastic materials is directed to an improved cartridge type control valve having elements which are fabricated of such plastics and can be assembled into an integral unit fully interchangeable with existing prior art cartridge type control valves made of other and more expensive materials, and adapted for use in existing forms of dispensing heads without requiring substantial changes in the castings or forgings of said dispensing heads in order to receive the cartridge type control valves in accordance with the present invention.
The applicant's device is cheaper to make because methods for fabricating plastic elements are used in the manufacture thereof and more particularly in the formation of the fluid transfer assembly which allows for reduction both in the cost of materials and the cost of labor in making and assembling the control valve.
Addtional advantages of the improved catridge type control valve disclosed herein are that it is lighter in weight and hence the shipping charges will be less when these devices are shipped in quantities, it is substantially chemically inert and therefor resists corrosion and it has other improved physical properties.